Explosive.



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EXPLOSIVE. i

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To all whom it may concern: v

Be it known that we, F nnnnnio LEWIS NATHAN, manager, l/VILLIAM RI-x'ro'UL, chief chemist, and FRANK BAKER, chemist, all of Ardeer Factory, Stevenston, in the county of Ayr, Scotland, have invented a certain new, and useful Improvement in and Relat ing .to Explosives, and do hereby declare that the following is a full, clear, and exact description thereof. 4

vThis invention relates to stabilizing of propellant explosives.

However carefully prepared, nitric esters, such as nitrocellulose, nitroglycerin, nitromannite and nitr ostarch, undergo a slow decomposition even at ordinary temperatures,

' with the result that these substances and mixtures containing one or more of them, are liable to deteriorate when kept for considerable periods. composition-referred to, if allowed to remain in contact with the unchanged esters, exert. an accelerating effect on the decomposition. Especially is this the case with explosives containing one or more members of the above-mentioned class of chemical compounds, and such explosives are liable to.

become not merely unser-viceable but dan- 'gerous. It is t-hereforeessential, in order to howe'ver, possesses certain disadvantages These properties tend to produce a want ofhomogeneity in the explosive, and ultimately dering which limit the stabilizing effects produced 1 by it. For instance, it is an exceedingly complex substance, some of the components of it being very much less active in their sta-. bilizing properties than others. It is, moro-- over, entirely insoluble in nitroglycerin;

to limit the stabilizing effects of this sub stance. We have discovered that certain other substances possess to a very high de-.

gree the power of absorbing the harmful products of decomposition, and thus of renmore stable nitric esters or mixtures containing them, to which they are added.

These substances are chemical compounds of The products of the de-' Specification of Letters Patent; *Pa.tentd Rial. 17 1914 Application filed June 4, 1913. Serial N,o.f771,623. H H I the S NH;,C0.0R, where an or aromatic. radical, and where one orboth of thehydrogen atoms-of the NH group is or are replaced by, a radical which, as in,-,the case of R,.may be alkyl oraromatic-provided that the compound contains at least one. aromatic radical such as phenyl, naphthvl or phanthryl whether at R or in substitution for either of the'hydrogen atoms of the NH, group. These substances are known as esters of substituted carbamic acids. i V

This invention consists therefore broadly in effecting stabilization of propellant ex- V plosives formed of lor containing a nitric ester by including therein one'or morejof these substances in suitable quantity. I Compoundsas referred to can be prepared by' acting on esters of chloroformic acid with Y prlmary or secondary aromatic amins. Thus ethyl chloroformic ester and anilin give phenyl urethane.

or the ethyl ester of phenyl-carbamic acid, whlle methyl anilin and ethyl chloroformic ester give methyl-phenyl-urethane C6115 V OHa N-uQ-OC:H5,} v or the ethyl ester of methyl-phenyl-carbamic acid.

Other substances belonging to this class of compounds can beprepared by the action of the alkali salts of phenols on urea chlorids. For example, sodium phenate in alcoholic solution is added to diphenylnrea -chlorid also in solution in alcohol, sodium chlorid separates out, while the phenyl ester of diphenyl-carbamic acid remains in solution and can readily be separated. This reaction is represented by the following equation Yet another methodof preparation of certain of these substances consists in acting on aromatic isocyanates' with alcohols or phenols; For example, phenyl isocyanate and phenol when heated with a small quantity of aluminium chlorid yield the phenyl ester of phenyl carbamic acid, thus:

These bodies are of course only examples of the class of bodies referred to.

In judging which substance or substances of the class is or are most suitable for use in any particular case, we are guided by the properties of the individual compounds, such as volatility, solubility in nitroglycerin, and the readiness with which they become nitrated. As these substances are introduced Nitroglycerin 30% Guncotton 65% Methyl-phenyl-urethane 5% These substances possess the property of combining or reacting with the decomposition product of nitric estersand thus preventing them from having any accelerating influence on'the decomposition of these esters. T he action of any of these substances, when introduced as a stabilizer into nitric esters or mixtures of them, consists apparently partly in their becoming nitrated by the nitrogen peroxid and other injurious decomposition products of the nitric esters, and partly in their reducing these acid bodies to compounds which have no action on the nitric esters. A further advantage which some of these urethane derivatives possess over mineral jelly and similar previously proposed substances is that of being sufficiently soluble in nitroglycerin. When bodies which are insoluble or only slightly soluble in nitroglycerin .are added to a nitroglycerin explosive they often exhibit a tendency to scparate out from the finished explosive either in the form of crystals or as an oil. Any separation of this nature is exceedingly disad vantageous for many reasons. The fact that some of these urethane derivatives are soluble in nitroglycerin is also important from another point of view, namely, that it tends to the production of a more homogeneous mixture and to the increase of the active mass of thestabilizerpresent. y i 1 We are aware that similar compounds have been used in connection with pyroxylin which we do not claim herein.

We claim 1. An explosive containing at least one highly nitrated nitric ester and an ester of a substituted carbamic acid containing at least one aromatic radical.

2. An explosive containing at least one nitric ester and an ester of a substituted carbamic acid containing an alkyl, and an aromatic radical in substitution respectively for the hydrogen atoms of the amino group.

3. An explosive containingnitrocellulose, nitroglycerin and methyl phenyl urethane.

4. An explosive containing, gelatinized together, nitrocellulose, nitroglycerin and an ester of a substituted carbamic acid containing at least one aromatic radical.

5. An explosive containing gelatinized t0 Y gether, nitrocellulose, nitroglycerin and an ester of a substituted carbamic acid c0ntaining an alkyl and an aromatic radical in substitution respectively for the hydrogen atoms of the amino group.

6. An explosive containing, gelatinized together, at least one highly nitrated nitric ester and an ester of a substituted carbamic acid containing at least one aromatic radical.

7 An explosive containing, gelatinized together, at least one nitric ester and an ester of a substituted carbamic acid containing an alkyl, and an aromatic radical "in substitution respectively for the hydrogen atoms of the amino group.

8. An explosive containing, gelatinized together, nitrocellulose, nitroglycerin and methyl phenyl urethane. I

In testimony that we claim the foregoing we have here into set our hands.

FRE ERIC LEWIS NATHAN. WILLIAM RINTOUL. FRANK BAKER.

Witnesses:

M. B. MILNE, ERNEST HANSFORD.

Copies at this patent may be obtained for five cents each. by addressing the Oomminloner of intents. Washington, D. C." 

